Burner and nozzle tip for projecting hot products of combustion



R. A. FULLER Oct. 21, 1952 f BURNER AND NOZZLE TIP FOR PROJECTING HOTPRODUCTS OF COMBUSTION Filed Oct. 22, 1947 INVENTOR HUBERT AFULLER fw.am

ATTORNEY Patented Oct. 21, 1952 BURNER NOZZLE TIP FOR PROJECT- v ING HOTPRODUCTS OF COMBUSTION Robert A. Fuuer, yilhilaslelphia, Pa., assignerto Selas Corporation of America, Philadelphia, Pa., a corporation ofPennsylvania Application October 22,1947, Serial No. 781,403

The present invention relates to high tempera.- ture gas burners. It isan object of the invention to provide a gas 'burner which will produceajhigh velocity stream 'of hot gases in the general form of a hollow,truncated pyramid or cone.v It is a further ob- 'ject of the inventionto provide a gas burner,

. the nozzle or tip of which will direct the hot,

high velocity products of combustion from a gas burner in a hollowconverging pattern.

"According to the presenty invention, a thread of molten material ispermittedto fall vertically 'into a horizontally directed stream of"hot, high 'Velocity gases which are so patterned that the thread -iscompletely enveloped by the gases. rConsequently thev thread is carriedby the gases *and is, in effect, exploded by them into a plurality offine fibersl of uniform quality. t The'various features ofnoveltywhichcharacterize my invention are pointed'ofut withparticularityin thevcla'ims annexed to land forming a part of thisspecincation, For a better understanding ofthe invention, however, itsadvan-` tages, and specific objects'attained with its use, referenceshould be had tothe accompanying drawings and descriptive matter inwhich I have illustrated and described a preferred embodiment of theinvention. In the drawings: A v v Figure 1 is a view, partly in section,showing the apparatus required to make fibers;l

Figure 2 is a section through the burner 5 Figure 3 is a front View ofthe burner tip; Figure-fl isa section through the burner tip, `takenalong lines 4 4 of Figure f fFigure 5fisa figure showing a diierentshape -port in the'burner tip; and i "Figure 6 is a top view oftheburner tip showing themanner in which the lgas blast is formed.

. In the manufacture'of ne b'ers according to the present invention,there is provided a suitable melting furnace that has a forehearth l inwhich islocated the molten material 2. The lower portion. of thisforehearth is provided with an orice 3 of approximately'l/fg" inVdiameter through which a stream or thread of molten material may fall;y As the-material falls it will gradually be reduced in diameter toapproximately le at a point about 8" .below theorince. By the timeitreaches this' point "it will still be molten but lslightlymoreviscousthan it was at the exit of Corice' 3*. At this point the'th'read 4 isenveloped iin a* blast of hot gases 5, that are showndiagramfimatically, which ygases are ejected from a burner 6,` l, l Y

"1o claims. (ci. 15s-99) Burner 6 is similar to prior burners of thetype in the manner in which the fuel is burned and the hot gases ofcombustion are produced. yThe tip ornozzle of the burner through whichthe gases are ejected, however, is of a novel shape,

vand produces a pattern 'of vgases by means of which the method ofblowing fine fibers according to this invention may be followed.

l the burner screen.

vend portion of the shell I9.

Referring to Figure 2 of the drawing, itr willfbe seen that the burner 6included in this invention has a ring-shaped 4base member 1 formed toprovide an inlet chamber 8 and an extension 9 that is threaded, and intowhich maybe connected a pipe I! carrying a suitable supplyof combustiblemixture. The base member 1 is formed with an inwardly extending shoulderl2 at its top to receive the lower anged'end I3 of a cricular burnerscreen I4 having a plurality of small apertures I5 extendingtherethrough.

At the top face of the base member 'l a ringsh'aped clamping plate i6 issecured by some'suitable means, such as screws Il, with the inner end ofthe plate overlying the flanged endof In order to obtain a gas tightseal about the screen, a gasket 8, such as asbestos, is interposedbetween the plateand the base member.

The large end of a cup-shaped shel1 or'outer casing i9 is removablysecured to the base member by 'bolts 2l. Within the metal shell 'isprovided a hollow body having a cavity forming a combustion space 22terminating at its upper end `in a discharge orice or outlet. In the"burner illustrated the hollow body comprises a number of par-ts of hightemperature refractory material including an annular member 2li whichsnugly fits around the upper portion of the burner screen.v

About the annular member is disposed the lower end of a cylindricalmember 23 which bears against the *clamping plate'li and 'extendsupwardly therefrom to the sloping or tapered upper Within this memberand forming therewith apart of the refractory space is disposed a secondhollow cylindrical member 2li, also of refractory 'mater-iai. The lowerend of this member bears against thetop surface of the annular memberEiland the upper end thereof bears against the larger end of an annularmember 25 which forms a restricted discharge space. yThis memberprojects to a point 'substantially even with theA end of the metal shell-and has its opening closed by a burner tipor nozzle 26'.`

Inorder.` to withstand the high temperatures produced "1n the combustionspace during the burner tipl or nozzle 26;

,verge toward their outer ends.

enveloped by the hot gases.

operation of the burner, the inner cylindrical member 24 and the upperannular member 25 may be formed of suitable refractory material, such asberyllium oxide which possesses rigidity and strength at hightemperatures. 'Ihe outer cylindrical member 23 is preferably formed ofrefractory material,l such as aluminum oxide, possessing good insulatingproperties and having adequate strength to Serve as the outer portion ofthe refractory wall. The burner screen I4 itself, may be formed ofrefractory material, such as aluminum oxide. Tip or nozzle 26r is shownherein as being formed of a high' temperature resistant metallic alloy,-but itfcould besrnadeof a suitable refractory if desire'dl ,f

The refractory wall parts just described', are

secured to one another and in the outer shell I9 by any suitablefirebrick cement as indicated at 21. Such high temperaturecementproduces'Y a rigid and unitary burner structure in which allofffthe refractory wallparts are unitedrto form the combustion space';

As isV shown in Figure 2 of the drawing, the outerend of the metalcasing" I9 is threaded to receive an annular 'collar 28 having in it aconical opening 29. This opening receives in turn the It will be noted'Ythat the annular collar 28-has al cut-out portion 3| that is closed by awasher 32 so that when the lburner tip, the washer, and the annularcollar -arein Yassembled relation with. respect tothe outer shellIsasmall annular space is provided.

This spaceY is usedffor circulating vcooling water so thatV the burnertip 2-6 and collar 28 will not become-overheated To thisfend an inlet-33 and an outlety 34 (Figure 3)\ are provided through Whichthe coolingwater may be passed. These parts,` aswell asthev ceramic parts whichwere described-above, are all cemented together with a suitable.high-temperature'cement so that when they arein assembled relation,as'shown inthe drawing, they will form a rigidy unitary memberVwit-ligas tight joints between each part.

The burner tip or nozzle 26 has in it a port 35v which is substantiallyU-shaped. This port is .provided with a horizontal portion 36 and twoupwardly extending portions 31 and 38 that -con- As shown best inFiguresl and 4-the upwardly extending Iportions ,of the 4slot are cutVat an angle toy the face of the burner tipso that the-r hot gases ofcombustionvfrom thecombustion chamber 22 passing throughtheport 35 inthe tip will take the form Aofha, U, the angle. of theA legs causing thegases to converge; The pattern of the gases is substantially that of ahollow truncated pyramid with a small triangular opening in the topthroughfwhich the thread 4 passes. This is best shown in dash linesvinFigure.

There is shownin Figure 5 another shapefor thel burner port. I-nV thiscase the port 35av is circular virl-'shape except for a short. portionof the arc across the top thereof. This leaves a space through which thethread may fall to .be As in the previously described embodiments, port35a is larger on the inner face of nozzle or tip 26 than it is on theouter face thereof. ThisA gives a converging pattern to the kport and tothe gases passing therethrough so that they form, in effect, a hollowtruncated cone with ano'peningin the top there- 6f. Whether the port isshaped as4 shown in Figure 3 or Figure 5, the pattern of the gases,4looking from above, will be substantially'the same fand similar' tothat shown .in Figure. lllngrboth cases the port may be said to besubstantially U-shaped with the vertical legs converging. The port maytake other shapes as long as the gases passing through it form a closedypattern with an opening in the top through which the thread 4 ofmaterial may fall.

In the operation of th'eburner 6 to' produce a high velocity stream of?the heated products of combustion, a fuel mixture comprising gas andcombustion supporting air is supplied through the inlet pipe .Il from asuitable source. When the burnerl isrelativ'ely cool and at a lowtemperature the' mixture supplied thereto passes through: theinletchamber 8, burner screen I4 and .thecombustion space 22, from whichit is discharged throughthe port 35 or 35a in the burner tip 26. Thecombustible mixture is initially supplied to the burner' at varelatively low pressure so that the gaseous mixture discharged from thisspace can be ignited to produce and maintain a flame at the outlet.

When a flame is being maintained at the outlet, the pressure of thegaseous mixturen supplied to theburner may be momentarily reducedsufficiently to cause the flame to backrethrough the outlet in theburner tip and into the combustion space22. When this occurs a pluralityof flames are produced and maintained at the upper ends of the smallapertures l5 in the burner screenl4.

When theA names are being maintained atthe top of the burner screen, thepressure of the gaseousv mixture supplied to the burner may then beincreased. After ashort interval of time the flames` maintained at thetop surfaceV of the burner. screen effect such heatingY of the innerrefractory lining24 that l.its surface is heatedto a highincandescenttemperature.V The. heating of the inner refractory liningto. ahighly. incandescent condition and radiant heat-therefrom promotessubstantially complete combustionv yof the mixture, before themixturereaches the port inthe burner tip. From this port `in the tip isdischarged a high velocity stream of heated gases at a temperaturenearly equal to the temperature of the combustion space, andconstituting ubstant'ially entirely heated'products of combusion.

In a burner of the type described, the heated products of combustion aredischarged from the combustion space through the port in the tip at anelevated temperature of approximately13000" F. and` ata velocity of..from 800 to.1000 feetper second..

The molten material from the forehearth l falls in a verticalv thread 4to a point. closely adjacent thefrontof the burner nozzle and betweenthe converging portions of the blast which'are ejected from theupstanding portions of thenozzle openings as shown in Figure 6. Thisthread of material will fall until it reaches thev lowerhorizontalsection of the blast where ii;v willY be blown to the left inFigure 1. As the thread moves away'from the front ofthe burner, it willbe completely enveloped in the high temperature gases of combustion thatarel being. discharged through the port 35 or 35a. I

Becauseof rthe pattern in'` which the gasesare formed asthey leave theburner tip, the thread 4 1s completely enclosed'by these gases.Therefore, there is no possibility of the thread bouncing oi or awayfrom the gases and consequently not beingy reduced. sufliciently insize; Since. the thread d is completely .enclosed by the gases whichare. above the temperature at which1 the material melts, the materialwhile being carried v.5 with the blast will be remelted to an extremelyfluent state and blown in a fine spray in the direction of the gas iiow.This fine spray of material forms a high grade of fibers.

While in accordance with the provisions of the statutes I haveillustrated and 'described the best form of embodiment of my inventionnow known to me, it will be apparent to those skilled in the art thatchanges may be made in the form of the apparatus disclosed withoutdeparting from the spirit of my invention, as set forth in the appendedclaims, and that in some cases certain features of my invention can beused to advantage without a corresponding use of other features.

What is claimed is:

l. A gas burner comprising a body having a combustion chamber formedtherein, said chamber having an inlet opening at one end and an outletopening at the other'end, means to supply fuel to be burned to the inletopening of said chamber,` a tip to close the outlet of said chamber,means to fasten said tip to said body, said tip being provided with anopening throughwhich the hot products of combustion produced in saidchamber may be exhausted, the opening in said tip being substantiallyU-shaped with the legs of theL U being closer together at their unjoinedends than at their joined ends.

2. A gas burner comprising a metallic shell, a ceramic lining in saidshell to form a combustion chamber having an inlet for fuel andcombustion air and an outlet for the products of combustion, a watercooled annulus attached to said shell surrounding said outlet, a tipmember held in position over vsaid outlet by said annulus, said tipmember being provided with an outlet port therein through which theAproducts of combustion pass, said port being substantially U-shaped,the portions of the port forming the legs of the U- converging from theside of the tip in the combustion chamber to the other side thereofwhereby the gases leaving said port will iiow in a converging pattern.

3. A gas burner comprising a hollow body forming a combustion chamberhaving an inlet opening and an outlet opening through which acombustible mixture and products of combustion may pass respectively, atip member, means lto attach said tip member to said body to close thesaid outlet opening, said tip member being provided with a port throughwhich the products of combustion flow said port being substantiallyU-shaped and of substantially uniform cross section, the portions of theport forming the legs of the U converging from the side of the tip inthe combustion chamber to the other side thereof whereby the gasesleaving said port will flow in a converging pattern.

vopening comprising a straight portion and a separate inclined portionconnecting at an acute angle with each end of said straight portion.

6. A burner tip of claim 5 in which the inclined portions are closertogether on the outside surface than they are on the inside surface ofsaid material.

'7. A gas burner comprising a body having a combustion chamber formedtherein, the chamber having an inlet opening at one end and an outletopening at the other end, means to supply fuel to be burned in saidchamber, a tip to cover the outlet end of said chamber, means to attachsaid tip to said body in a position to close the outlet opening of saidchamber, said tip being provided with a substantially flat surface beingformed with a slot through which products of combustion may bedischarged, said slot having a straight portion and two convergingportions communicating at an acute angle with said straight portion atthe ends thereof, each of said converging portions being so formed thatthe openings on the side of said tip toward `said chamber are furtherapart than the openings on the opposite side of said tip.

8. A gas burner comprising a body having a combustion chamber formedtherein, said chamber having an inlet at one end and an outlet openingat the other end, a tip for said burner attached to said body to closethe outlet opening of said chamber, said tip being provided with asubstantially flat surface having an opening therein comprising astraight portion and a pair of converging portions each communicatingwith an end of said straight portion at an acute angle thereto.

9. A tip for a burner comprising a body of material provided with a porttherein, said port being substantially U-shaped and of substantiallyuniform cross section, the portions of the port forming the legs of theU converging from` one side of the body of the material toward the otherside thereof whereby gases passing through said port from said one sidewill fiow in a converging pattern.

10. A tip for a gas burner and through which hot products of combustionare to be discharged comprising a body of material having opposedfaces,'said body having an opening, said opening being in the shape ofan arc and extending through more than the opening being ofsubstantially uniform cross section and larger on one face of said bodythan on the other face thereof whereby gases iiowing through saidopening from said one face will flow in a converging pattern.

, ROBERT A. FULLER.

REFERENCES CITED The following references are of record in the (ile ofthis patent:

UNITED STATES PATENTS Number Name y Date 1,140,655 Bell ,May 25, 19151,689,551 Hammond Oct. 30, 1928 1,901,086 Cox Mar. 14, 1933 1,977,406Powell Oct. 16, 1934 2,175,225 Slayter Oct. 10, 1939 2,178,871 DrillNOV. 7, 1939 2,367,119 Hess Jan 9, 1945 2,427,545 Berger Sept. 16, 19472,481,543 Stalego Sept. 13, 1949

